Technology Review has an interesting piece on a Yale team developing a robotic grabber actuated from a helicopter. The Yale Aerial Manipulator, could be used in spots that are difficult for ground robots to get to, such as high, roughly terrained places, or back yards.

It can currently carry objects that weigh up to two kilograms at speeds reaching 130 kilometers an hour. Being that's roughly the weight of a couple grenades, any bets on how long till it's weaponized?